Single column immunological test elements

ABSTRACT

A plurality of individual single column test elements are provided for use in a clinical testing apparatus. Each test element is defined by a single test column that includes a quantity of a test material, such as gel material or a bead matrix, including a cover strip used to access the contents of the test column. Individual test elements can be stored, retained and dispensed for testing patient samples.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Ser. No.12/175,590, filed on Jul. 18, 2008, the entire contents of which areherein being incorporated by reference.

FIELD OF THE INVENTION

This invention relates to the field of immunodiagnostic testing and morespecifically to a test element defined by a single disposable column orreaction well that can be used as a replacement for a multiple fixedcolumn gel card or bead cassette test element. Single element columnscan be dispensed and used either individually or selectively in groupsdepending on a specific test or application.

BACKGROUND OF THE INVENTION

Conventionally, it is known to utilize test elements such as gel cardsor bead cassettes for blood grouping, antigen or antibody testing, orother related immunohematological applications or uses. These testelements commonly include a planar substrate that supports a pluralityof optically transparent and vertically arranged columns or reactionwells. Each of the reaction wells retain a quantity of an inertmaterial, such as glass beads or a gel material, that is mixed within asuspension having an antigen or antibody or is bound therewith. In usein automation, an upper foil layer of at least one card or cassette ispierced or removed, permitting access to the contents of at least one ofthe reaction wells of the test element for adding patient sample. Thesample is then incubated and centrifuged to accelerate an agglutinationreaction by means of column agglutination technology (CAT) in whichbound red blood cells clump and are filtered by the inert materialmatrix. The cards or cassettes are usually prearranged and include afixed and predetermined number of columns to enable a test of interest(e.g., direct or indirect Coombs test, Rh blood typing, ABO bloodtyping) to be completed.

There may be instances or examples in which all columns of a test cardor test cassette may not be necessary in order to conduct a test ofinterest. However, such test elements, once at least one column thereofis pierced, are often disposed of and not reused, even if availableunpierced reaction wells remain in a test element creating unnecessarywaste and expense. Moreover, there are a number of situations in whichvarying the number of test columns is advantageous. Therefore, there isa need to provide versatility as to the types of test elementsavailable, particularly in automated test apparatus.

There is also a general and prevailing need in the field to reduce theoverall footprint of automated testing systems, including those systemsthat employ test elements, such as those that are noted above. To thatend, providing any suitable means for reducing or economizing the sizeof a test element, for storage or otherwise, would be greatly desired.

SUMMARY OF THE INVENTION

According to one version, there is provided a test element for use in animmunodiagnostic test apparatus, said test element comprising a singlereaction well having an inert material disposed therein as well as asuspension containing an antigen or antibody or a carrier-bound antigenor antibody and a wrap or seal covering the reaction well. The sealaccording to one version is selectively pierceabie in order to permitaccess to the contents of the reaction well.

According to another aspect, there is provided a cartridge comprising aframe that retains a plurality of test elements, each said test elementcomprising a single reaction well having an inert material disposedtherein as well as a suspension containing an antigen or antibody or acarrier-bound antibody or antigen as well as a wrap or seal covering thereaction well. The cartridge dispenses the individual test elements foruse, whether individually or selectively in any useful number, providingsignificant versatility and improving overall throughput.

According to another aspect, there is provided an automated testingapparatus comprising a test element supply including a plurality ofsingle column test elements.

Preferably, the automated testing apparatus further includes anincubator and a centrifuge that are each enabled for handling theindividual single column test elements whether the test elements arehandled individually or within cartridges containing selectivelyvariable numbers of said test elements. As such, the testing apparatuscan be configured to operate with a plurality of cartridges betweencomponents or modules of the testing apparatus or to provide differentassays in conjunction with a test card.

One advantage is a realized reduction in storage capacity volume thatcan be achieved using the above noted individual test elements in anautomated test apparatus, wherein this reduction can be greater than 50percent.

Another advantage realized is that the individualized test elementsprovide truly random access capability and scheduling in an automatedtesting apparatus. In addition, throughput enhancement is realized dueto reduction in the waiting time for batches

Yet another advantage realized is cartridge-based packaging ofindividualized or single column test elements permits easier loading andhandling of test elements than found in previously known testingsystems.

Still another advantage is that providing individualized test elementsinsures that there is no reuse of unused columns as in present testelements.

Yet still another advantage provided herein is that the individual testelements enable an extremely small- and efficient footprint to beprovided in conjunction with test apparatus including those of testelement storage, as well as permitting enhanced designs to componentsand modules used in typical testing apparatus including, for example,centrifuges, incubators, transport assemblies, readers and othercomponents.

The present design is largely facilitated to automated processes andprovides better safety as a result. However, the herein describedconcepts can also be applied to manual based test systems.

These and other features and advantages will become readily apparentfrom the following Detailed Description, which should be read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a prior art immunodiagnostic test element;

FIG. 2 is a top plan view of a prior art automated test apparatus thatutilizes at least test elements, such as those depicted according toFIG. 1;

FIG. 3 is a front view of a single column test element in accordancewith one embodiment;

FIG. 4 is a top plan view of the single column test element of FIG. 3;

FIG. 5 is a side view of a linear array cartridge of single column testelements FIGS. 3 and 4;

FIG. 6 is a top plan view of the cartridge of FIG. 5;

FIG. 7 is a front view of a single element dispensing cartridge inaccordance with another embodiment; and

FIG. 8 is a top plan view of the dispensing cartridge of FIG. 7.

DETAILED DESCRIPTION

The following discussion relates to a compact consumable test elementfor patient or other sample testing as well as applications for thesingle column test element, preferably for use in conjunction withautomated test apparatus. It will be apparent to those of sufficientskill from the following description that numerous variations andmodifications are possible within the intended scope of the conceptsdescribed. In addition, certain terms such as “top”, “bottom”, “above”,“below” and the like are used herein in order to provide a suitableframe of reference with regard to the accompanying drawings. Theseterms, however, are not intended to be overly limiting, except where sospecifically indicated.

Referring to FIG. 1, there is shown a prior art test element 20 in theform of a so-called “gel card” or “bead cassette”. This element 20 iscommonly defined by a planar substrate made from a durable plasticmaterial 26, the substrate having a top side 27 and an opposing bottomside 28. The substrate 26 supports a plurality of optically transparentand vertically arranged test columns or reaction wells 34, each of thereaction wells also being made from a plastic material. In theembodiment shown, a total of six (6) reaction wells 34 are integrallyformed within the substrate 26. Each of the reaction wells 34 arefurther defined by an upper portion 37 having an inner diameter that issignificantly larger than that of a lower portion 41. A transitionalportion 39 having an inwardly tapering diameter interconnects the upperand lower portions 37, 41. A quantity of an inert material (not shown),such as glass beads or gel material, is provided preferably by themanufacturer within the lower portion 41 of each column, this materialbeing mixed with an antigen or antibody or a carrier-bound antibody orantigen typically in an aqueous suspension or medium. A seal or wrap 50is attached, such as a pierceable foil, covering the top side 27 of thetest element 20 that, when pierced or removed, selectively permitsaccess to the contents of the reaction wells 34. The test element 20further includes a label 54 located beneath the reaction wells 34 on afront facing side thereof, the label including a bar-coded portion 55,the label and bar-coded portion each including items such as lot number,test type, expiration date, place of manufacture and other information.Additional details relating to the above test elements 20 can be foundin U.S. Pat. No. 5,512,436, the entire contents of which are hereinincorporated by reference.

The herein described immunodiagnostic test element 20 can be used in anautomated testing apparatus 60, such as that shown in FIG. 2. In briefand according to this prior art embodiment the testing apparatus 60includes a frame 64 that retains a number of components including areagent and sample supply 70, an incubator station 80, a centrifuge 90,an analysis station 100, and a drawer assembly 190. More particularly,the sample and reagent supply 70 of this specific apparatus 60 includesa sample rack 74 as well as a reagent rack 78, each of which containbottles or vials of patient sample and reagent, respectively. Thereagent and sample supply 70 is constructed as a rotor that is rotatableabout a center axis by means of a drive mechanism that includes a motor(not shown in this view), wherein a bar code reader 79 is furtherprovided in relation to the reagent and sample supply 70 as well as atube hold-down assembly 76 disposed over a portion thereof.

The incubator station 80 includes a cassette rack 82 that furtherincludes respective first and second sections 84, 86, as well as a drivemechanism including a motor 88 that selectively rotates each of thesections about a center axis. The centrifuge 90 is known to those in thefield and includes a rotor 94 and a motor 98 enabling reactant containedwithin supported cards to be spun down by centrifugation. The analysisstation 100 includes holding means 102, illumination means 104, animaging subsystem 106, a processing subsystem 108, a transport subsystem110, a storage rack 115, a bar code reader 112, and a waste receptacle116. The drawer assembly 190 includes a drawer (not shown), a slide tray(not shown), a motor (not shown), a sensor bar 196, a bar code reader198 and a holding area 197. A transport assembly (not shown) of thetesting apparatus 60 includes a robot arm and a gripper. Finally, apipette assembly includes a gantry-type pipette that is attached to arobot arm 128, this assembly further including shallow and deep washareas 122, 125, as well as cell dilution packs 127.

In the testing apparatus 60 shown, for example, a plurality of testelements 20, such as those previously described according to FIG. 1, areinitially supported within the drawer and are read by the bar codereader 198. Assuming the read of the test element 20 is successful, thetest elements 20 are loaded by means of the transport assembly (notshown) and the gripper into the cassette rack 82 of the incubator 80. Apiercing assembly (not shown) is disposed above the first and secondsections 84, 86 of the cassette rack 82 of the incubator station 80 andincludes a support subassembly having a slide support (not shown)defined by a plurality of puncture needles that are reciprocablymovable, such as by means of solenoids (not shown). The incubatorstation 80, as driven by the motor 88, is used to incubate patientsample added to each of the test columns 34 from one of the vials of thesample rack 74, the incubator further including the assembly 76 thatholds down the sample and reagent vials. The pipette of the pipetteassembly is used to aspirate sample from the sample rack 74, while thepiercing assembly (not shown) is used to puncture each of the reactionwells 34 of the then-incubated test elements 20. Once the puncturingstep has been completed, the pipette 124 can then be used to dispense apredetermined quantity of patient sample (and possibly additionalreagents) from the sample and reagent supply 70 into each of thereaction wells 34, FIG. 1, wherein the mixture can be suitablyincubated.

Following incubation and in the described testing apparatus 60, the testelements 20 are removed from the incubator station 80 by means of thetransport assembly to the centrifuge 90 wherein the test elements arethen spun down, thereby accelerating an agglutination reaction as redblood cells are clumped together in the presence of coated reagents. Theplurality of beads disposed in each reaction well 34 of the test element20 includes particles having diameters ranging between about 10 and 100microns, providing a matrix for the red blood cells, but not the heavierformed agglutinates to pass through by filtering. The resulting reactioncan be imaged within the analysis station 100 of the testing apparatus60 by means of the illumination assembly 104 and imaging subsystem 106,the latter being connected to the processing subsystem 108 havingmachine vision for grading of the reaction. Additional detailsconcerning the foregoing testing apparatus 60, including its mode ofoperation, are provided in commonly-assigned U.S. Pat. No. 5,578,269 toYaremko et al., the entire contents of which are herein incorporated byreference.

To that end, each station of the testing apparatus 60, such as theincubator station 80, centrifuge 90 and analysis station 100, musttherefore accommodate the test elements 20 and as a result thesestations must each be sized appropriately in order to retain same. Inthe above test apparatus 60, the individual modules must thereforeaccommodate the entire test card or element 20, FIG. 1, even if all ofthe columns of the test element are not actually used or required fortesting.

With the preceding background and referring to FIGS. 3 and 4, there isshown a consumable test element 200 made in accordance with a firstembodiment. The test element 200 is defined by a compact body 204preferably made from a lightweight plastic moldable material that isfurther defined by a single vertically arranged column or test chamber208 therein. The column 208 extends downwardly from a top side 210 ofthe element 200 and is further defined by an upper section 212 having aninner diameter that is significantly larger than that of a lower section216. An inwardly tapering transitional section 220 is disposed betweenthe upper section 212 and the lower section 216. The test element 200,and more particularly the test column 208, is optically transparent forpurposes of detection of reactions occurring therein. A quantity of aninert material (not shown), such as beads or gel material, is added tothe lower section 216 of the test column 208 along with a reagent thatincludes an antigen or antibody or a carrier-bound antigen or antibodyformed in an aqueous slurry or medium. A wrap 224 is also added to thetop side 210 of the element 200, such as a foil that is adhesively orotherwise attached, to effectively seal the contents of the column 208in a manner that is commonly known and to protect the contents fromcontamination. The wrap 224 is preferably and selectively piercable toaccess the contents of the element 200.

Referring to FIG. 5 and according to the present embodiment, a plurality(e.g., at least two) of the above-described single column test elements200 can be individually fitted within a cassette or cartridge 230. Thecartridge 230 is defined, according to this embodiment, by a frame 234having exterior surfaces including a bottom surface and a set of lateralsurfaces that are formed in a substantially rectangular configuration,which combine to form an enclosure. The frame 234 according to thisembodiment is sized to maintain a predetermined number of test elements200 in close fitting and adjacent relation with each other in a lineararray 238. The number of test elements 200 that are retained as acartridge can easily be varied depending on the dimensions of the frame234 that is used. According to this embodiment, the lateral walls of theframe 234 are defined by a height dimension that is essentially equal tothat of the test elements 200. In this instance and referring to FIGS. 5and 6, twenty five (25) test elements 200 are arranged in aone-dimensional linear array 238 for dispensing, such as within anautomated testing apparatus (not shown). Moreover, the linear array 238as shown, permits the test elements 200 to be individually dispensedfrom an end position 242 of the frame 234 through an appropriately sizedslot 246 wherein the cartridge defined herein can function as a testelement supply. Therefore and in the array 238 depicted, a test element200 is ejected vertically through the slot 246, but it will be readilyunderstood by those of adequate skill in the field that the array canassume other configurations such that test elements 200 can bedispensed, for example, horizontally.

In an alternate version, the test elements 200 can also be separatelyarranged, for example, within a cartridge that like the preceding isdefined by a frame sized to permit storage of a plurality of the abovedescribed single element test elements. For example, and as shown inFIGS. 7 and 8, a cartridge 280 is defined by a frame 284 that is sizedto maintain a two dimensional array of test elements 200 wherein thetest elements can be individually dispensed therefrom. In this specificversion, ninety six (96) test elements 200 can be retained in closefitting and adjacent relation within the confines of an assemblagehaving 16 columns and 6 rows totaling 96 test elements, though thespecific number of columns and rows can easily be varied depending ofthe use required and the test apparatus. In this latter version, testelements 200 can actually be repackaged within at least one smallerframe that are sized to retain a specific number of test elements (e.g.2-8 test elements) depending on the test that is to be performed.

in another version, the test elements can be dispensed from either ofthe previously described frames into a separate test cartridge 300 thatis sized to retain a predetermined number (e.g., greater than two) oftest elements 200. As such, the cartridge 300 can be adequately sized toretain any number of test elements wherein the entire cartridge can beloaded and unloaded into modules of the test apparatus (e.g., incubator,centrifuge, etc).

PARTS LIST FOR FIGS. 1-8

-   20 test element-   26 substrate, planar-   27 top side-   28 bottom side-   32 inert material-   34 reaction wells or microcolumns-   37 upper portion-   39 transitional portion-   41 lower portion-   50 seal or wrap-   54 label-   55 bar-coded portion-   60 testing apparatus, automated-   64 frame-   70 sample and reagent supply-   74 sample rack-   78 reagent rack-   79 bar-code reader-   80 incubator station-   84 first section-   86 second section-   88 motor-   90 centrifuge-   94 rotor-   98 motor-   100 analysis station-   102 holding means-   104 illumination assembly-   106 imaging subsystem-   108 processing subsystem-   110 transport subsystem-   112 bar code reader-   115 storage rack-   116 waste receptacle-   122 shallow wash area-   125 deep wash area-   127 cell dilution packs-   128 robot arm-   190 drawer assembly-   195 motor-   196 sensor bar-   197 holding area-   198 barcode reader-   200 test element-   204 compact body-   208 test chamber or column-   210 top side-   212 upper section-   216 lower section-   220 transitional section-   224 wrap-   230 cartridge-   234 frame-   238 linear array-   242 end position-   246 slot-   280 cartridge-   284 frame-   300 cartridge

Though only specific embodiments were described herein, it will bereadily apparent that other variations and modifications are possiblewithin the intended ambits of the present invention, according to thefollowing claims.

1. A method for random access operation of a clinical analyzer, saidmethod including the steps of: providing a storage frame retainingtherein a plurality of individual test elements, each of said testelements including a single reaction well containing a quantity of testmaterial for testing a patient sample and a strip sealing said reactionwell; selectively dispensing at least one of said test elements fromsaid storage frame; and conducting a test using said at least one ofsaid individual test elements.
 2. A method as recited in claim 1,wherein said test element includes a quantity of an inert test materialand a reagent containing at least one of an antibody and a antigen, saidmethod including the additional steps of: adding patient sample to saidreaction well; centrifuging said test element to accelerate anagglutination reaction within said reaction well; and visually detectingsaid reaction,
 3. A method as recited in claim 1, wherein said methodincludes the additional steps of providing at least one cartridge, saidat least one cartridge being sized to contain at least two of said testelements needed for a test and dispensing at least one test element fromsaid storage frame into said cartridge prior to conducting said test. 4.A method as recited in claim 2, wherein each said that element includesa cover strip, said method including the step of piercing said coverstrip to access the contents of said test element prior to said patientsample adding step.
 5. A method as recited in claim 3, wherein thecartridge is sized to fit between 2 and 8 dispensed test elements fromsaid storage frame.
 6. A method as recited in claim 1, wherein said testelements are made from an optically transparent material.
 7. A method asrecited in claim 6, wherein said cartridge is made from an opticallytransparent material.
 8. A method as recited in claim 1, wherein saidstorage frame retains said individual test elements in an array.
 9. Amethod as recited in claim 8, wherein said array is linear.
 10. A methodas recited in claim 8, wherein said array is two dimensional.